Chapter 20: Terms to Know

1. Genetic engineering

2. Biotechnology

3. Recombinant DNA

4. Gene cloning

5. Restriction enzymes

6. Sticky ends

7. DNA ligase

8. Cloning vector

9. Nucleic acid hybridization

10. Genomic library

11. cDNA library

12. PCR

13. Gel electrophoresis

14. Southern blotting

15. DNA microarray assays

16. SNPs

17. RFLPs

18. Stem cells

19. Gene therapy

20. GMO (genetically modified organism)

What You Must Know:

The terminology of biotechnology.

The steps in gene cloning with special attention to the biotechnology tools that make cloning possible.

The key ideas that make PCR possible.

How gel electrophoresis can be used to separate DNA fragments or protein molecules.

Genetic Engineering: process of manipulating genes and genomes

Biotechnology: process of manipulating organisms or their components for the purpose of making useful products.

Recombinant DNA: DNA that has been artificially made, using DNA from different sources eg. Human gene inserted into E.coli

Gene cloning: process by which scientists can product multiple copies of specific segments of DNA that they can then work with in the lab

Tools of Genetic Engineering

Restriction enzymes (restriction endonucleases): used to cut strands of DNA at specific locations (restriction sites) Restriction Fragments: have at least 1

sticky end (single-stranded end)

DNA ligase: joins DNA fragments

Cloning vector: carries the DNA sequence to be cloned (eg. bacterial plasmid)

Using a restriction

enzyme (RE) and DNA ligase

to make recombinant

DNA

Gene Cloning

Applications of Gene Cloning

Techniques of Genetic Engineering

PCR (Polymerase Chain Reaction): amplify (copy) piece of DNA without use of cells

Gel Electrophoresis: used to separate DNA molecules on basis of size and charge using an electrical current (DNA + pole)

Gel Electrophoresis: used to separate DNA molecules on basis of size and charge using an electrical current (DNA + pole)

Cloning OrganismsCloning Organisms

Nuclear transplantation: nucleus of egg is removed and replaced with nucleus of body cell

Nuclear Transplantation

Problems with Reproductive Cloning

Cloned embryos exhibited various defects

DNA of fully differentiated cell have epigenetic changes

Stem Cells

Stem cells: can reproduce itself indefinitely and produce other specialized cells Zygote = totipotent (any type of cell) Embryonic stem cells = pluripotent (many cell

types) Adult stem cells = multipotent (a few cell types)

or induced pluripotent, iPS (forced to be pluripotent)

Embryonic vs. Adult

stem cells

Using stem cells for disease treatment

Applications of DNA Technology

1. Diagnosis of disease – identify alleles, viral DNA

2. Gene therapy – alter afflicted genes

3. Production of pharmaceuticals

4. Forensic applications – DNA profiling

5. Environmental cleanup – use microorganisms

6. Agricultural applications - GMOs

Gene therapy using a retroviral vector

“Pharm” animal: produce human protein secreted in milk for medical

use

DNA Fingerprinting

RFLPs (“rif-lips”)

Restriction Fragment Length Polymorphism

Cut DNA with different restriction enzymes

Each person has different #s of DNA fragments created

Analyze DNA samples on a gel for disease diagnosis

Outdated method of DNA profiling (required a quarter-sized sample of blood)

RFLPs – Disease Diagnosis

STR Analysis

STR = Short Tandem Repeats

Non-coding DNA has regions with sequences (2-5 base length) that are repeated

Each person has different # of repeats at different locations (loci)

Current method of DNA fingerprinting used – only need 20 cells for analysis

STR Analysis

STR Analysis

Biotechnology TechniquesHow to make

Recombinant DNA

Gel Electrophores

isPCR

Summarize: What is this technique?

Draw and label a diagram to show this technique

What are the main tools or

materials involved?

Applications: What is this

being used for?